3Dpass to EVM Address Converter

The app allows for an easy conversion of 3Dpass substrate-based SS58 address to EVM H160 format and vice versa.

Networks Support

The converter supports both mainnet and testnet:

• 3Dpass - The Ledger of Things Mainnet (SS58 prefix: 71)
• 3Dpass - The Ledger of Things Testnet (SS58 prefix: 72)

Install

pnpm install

Run

pnpm start

Address Mapping

There is an EVM compatibility layer operating on The Ledger of Things (LoT) to ensure Solidity smart contracts seamless execution. The EVM accounts are standard H160 addresses (20 bytes), while the native accounts are using the H256 format (32 bytes).

Conversion Logic

The conversion between native and EVM addresses is implemented using the libraries (@polkadot/util and @polkadot/util-crypto).

H256 to H160 Mapping (Native to EVM)

The conversion from native H256 to EVM H160 is straightforward:

1. The native public key (32 bytes) is truncated to 20 bytes by taking the first 20 bytes
2. The resulting 20 bytes are converted to a hex string with '0x' prefix

Example:

Native H256: 0xc6006fea43ccce14f9432f8e6b9403113c935cc17160cd438af2e7a02624124c
SS58: d1GjLAyfV83DefL1z1HpJwuXxWJhD3PHUArFgaZsKn321pUK4

Maps to EVM H160: 0xc6006fea43ccce14f9432f8e6b9403113c935cc1

This approach ensures that the original public key owner maintains full control while accessing both systems: Native runtime and EVM.

H160 to H256 Mapping (EVM to Native)

The conversion from EVM H160 to native H256 is more complex due to the information loss in the original truncation. Since we can't recover the original 32-byte key from a 20-byte address, a deterministic mapping is used:

1. The EVM address (20 bytes) is validated using isEthereumAddress check
2. The address is then processed through the evmToAddress function which:
   • Takes the EVM address and prepends it with a specific prefix (0x000000000000000000000000)
   • Applies the Blake2b hash function to generate a 32-byte output
   • The resulting hash is used as the new public key
   • This new key is different from the original one but maintains a consistent mapping
   • The resulting key is encoded in SS58 format with the appropriate network prefix (71 for mainnet, 72 for testnet)

Example:

EVM H160: 0xc6006fea43ccce14f9432f8e6b9403113c935cc1

Maps to Native H256: 0xceb75620b9f3bc3a039b8e78efed58fa3c7422d18c97f1fd44abf3f2499d0760
SS58: d1GvktUdvKdghY7LB2zW2XDp1Wzio9ZPGGFcyaYhp2Nasy5LS

The mapped native account is a system address that allows receiving funds and executing transactions on behalf of the H160 address within the native runtime. However, the EVM address owner doesn't have access to the mapped H256 address private key and can only interact with EVM logic.